If you like ideas like this I highly recommend flatland by Edwin A. Abbott.

It’s available for free here: www.gutenberg.org/files/201/201-h/201-h.htm

Part one is a lot of social and religious critiques of the time it was written (1884 for second edition). Part two covers a lot more of the questions you brought up.

Warning: it is a work of fiction. Don’t expect hard science but my understanding is a lot of the ideas expressed here match modern math ideas.